Electrothermal simulation of large-area semiconductor devices

The lateral charge transport in thin-film semiconductor devices is affected by the sheet resistance of the various layers. This may lead to a non-uniform current distribution across a large-area device resulting in inhomogeneous luminance, for example, as observed in organic light-emitting diodes. The resistive loss in electrical energy is converted into thermal energy via Joule heating, which results in a temperature increase inside the device. On the other hand, the charge transport properties of the device materials are also temperature-dependent, such that we are facing a two-way coupled electrothermal problem. It has been demonstrated that adding thermal effects to an electrical model significantly changes the results. We present a mathematical model for the steady-state distribution of the electric potential and of the temperature across one electrode of a large-area semiconductor device, as well as numerical solutions obtained using the finite element method

Quantum Yield Measurement of Fluorescent Zeolite Nanopigments

Organic fluorescent molecules are infiltrated in the channels of zeolite L nanocrystals, thus creating organic-inorganic fluorescent nanoparticles. Combined with dielectric matrices, these fluorescent nanopigments open the way to the realization of novel optical devices. In this paper, the optical measurement of the quantum yield of fluorescent zeolites by means of a precise and reliable diffuse reflectance technique is presented. Several possible factors that may affect the fluorescence quantum yield are also investigated

Roadmap on holography

From its inception holography has proven an extremely productive and attractive area of research. While specific technical applications give rise to 'hot topics', and three-dimensional (3D) visualisation comes in and out of fashion, the core principals involved continue to lead to exciting innovations in a wide range of areas. We humbly submit that it is impossible, in any journal document of this type, to fully reflect current and potential activity; however, our valiant contributors have produced a series of documents that go no small way to neatly capture progress across a wide range of core activities. As editors we have attempted to spread our net wide in order to illustrate the breadth of international activity. In relation to this we believe we have been at least partially successful.This work was supported by Ministerio de Economía, Industria y Competitividad (Spain) under projects FIS2017-82919-R (MINECO/AEI/FEDER, UE) and FIS2015-66570-P (MINECO/FEDER), and by Generalitat Valenciana (Spain) under project PROMETEO II/2015/015

Optical spectroscopy of antimonide compounds: from GaSb epitaxial layers to AlGaSb/GaSb quantum systems

Dottorato di ricerca in fisica. 12. ciclo. A.a. 1998-99. Tutore Giorgio Guizzetti. Coordinatore Sergio P. RattiConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Fourier analysis of Bloch wave propagation in photonic crystals

The standard representation of an optical field propagating in a photonic crystal (PhC) is an electromagnetic Bloch wave. We present a description of these waves based on their Fourier transform into a series of electromagnetic plane waves. The contribution of each plane wave to the global energy and group velocity is detailed, and the valid domain of this decomposition is discussed. This description brings new insight to the fundamental properties of light propagation in PhCs. Most notably, it permits a continuous description of light propagation from the homogenous medium to the strongly modulated PhC case. It also provides an original physical understanding of negative refraction in PhCs and resolves inconsistencies that result from band folding

Wearable light management system for Light stimulated healing of Large area chronic wounds

<p>Presentation on February 13, 2016, at the SPIE Photonics West conference.</p

Color conversion films comprising polymer-substituted organic fluorescent dyes

The present invention concerns a color conversion film comprising at least one active layer, said layer comprising an organic fluorescent dye containing a fluorescent core, wherein said dye is substituted with at least one polymer segment. It also concerns its method of preparation